System 7 (Macintosh)

System 7 is the term used to refer to the Mac OS that superseded the earlier versions known simply as "The System", or "System 6", and before the use of the term "Mac OS" came into official use. The name reflects the version number of the OS - 7.0, but the term is also used to apply to all the 7.x versions.

System 7.0 was released for the Apple Macintosh in 1990. It offered a number of system enhancements that were either previously not available, or were optional extensions to the operating system.

Compared with System 6.x and earlier, System 7 offered:

• Built-in co-operative multitasking. Previously this function was available through MultiFinder in System 6.0, or not available at all. Because more than one application could run at a time, Desk Accessories were deprecated, System 7 treating them no different from other applications.

• Aliases - small files that "pointed to" other files on the system. This was added to help the user navigate the increasingly larger disks that were starting to appear.

• Applescript. This was an entire architecture for making scriptable applications. While complex, this feature was powerful and popular, and is still available to this day as part of Mac OS X.

• 32-bit QuickDraw was included as standard - previously available as a system extension.

• Publish and Subscribe. This feature permitted data "published" by one application to be imported ("subscribed") by another, and the data could be updated dynamically. The feature was not terribly popular with programmers, who found the API unweildy, and users didn't seem all that interested either. Relatively few applications ended up adopting it.

• A new full-colour user interface was included which gave a neat colour appearance on colour machines but which gracefully dropped back to the standard black and white interface on machines not supporting colour.

• A new Sound Manager API which replaced the older ad-hoc APIs that did not abstract the hardware to any great degree.

There were also a large number of architectural changes to make the OS more coherent and stable. Apple boasted on its release that System 7 was "rock solid", and while it was a great improvement over the earlier systems, the claim was rather hyperbolic.

System 7.0 was adopted quite rapidly by Mac users, and quickly became the base requirements for new software. Until the advent of OS X, System 7 was by far the largest shake-up and revamp of the Mac OS since its inception - even the so-called System 8.0 and Mac OS 9 were minor upgrades from System 7.x, compared to the changes from 6.x to 7.0

The coding group within Apple responsible for System 7 were known as the "blue meanies" after the blue slips of paper on which were written the features that could be implemented in a relatively short time. In comparison, the pink-slipped features were handled by the Pink group, later becoming the ill-fated Taligent project. Despite the idea of System 7 being the "quick win", it was still delivered several years late.